​The inorganic oxide phosphor, Y3−xCexAl5O12 is one of the most important yellow-emitting luminescent materials for solid-state white lighting applications. However, the light conversion efficiency of Y3−xCexAl5O12 is significantly reduced at high temperatures, which is known as thermal quenching. The mechanisms for thermal quenching are primarily associated with the electronic and vibrational properties of the materials. This presentation focuses on understanding different thermal quenching mechanisms through using different spectroscopes and time-resolved luminescence experiments.